18918145 has 4 divisors (see below), whose sum is σ = 22701780. Its totient is φ = 15134512.

The previous prime is 18918143. The next prime is 18918157. The reversal of 18918145 is 54181981.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3370896 + 15547249 = 1836^2 + 3943^2 .

It is a cyclic number.

It is not a de Polignac number, because 18918145 - 2¹ = 18918143 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18918143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1891810 + ... + 1891819.

It is an arithmetic number, because the mean of its divisors is an integer number (5675445).

Almost surely, 2^18918145 is an apocalyptic number.

It is an amenable number.

18918145 is a deficient number, since it is larger than the sum of its proper divisors (3783635).

18918145 is an equidigital number, since it uses as much as digits as its factorization.

18918145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3783634.

The product of its digits is 11520, while the sum is 37.

The square root of 18918145 is about 4349.4993964823. The cubic root of 18918145 is about 266.4564167400.

The spelling of 18918145 in words is "eighteen million, nine hundred eighteen thousand, one hundred forty-five".